Ice making



T. G. FCSTER July 24, 1962 ICE MAKING 2 Sheets-Sheet 1 Filed July 5,1960 FIG. I

INVENTOR. THEODORE G. FOSTER ATTORNEY.

T. G. FOSTER July 24, 1962 ICE MAKING 2 Sheets-Sheet 2 Filed July 5,1960 INVENTOR.

THEODORE e. FOSTER ATTORNEY.

same.

3,045,438 ICE MAKING Theodore G. Foster, North Syracuse, N.Y., assignorto Carrier Corporation, Syracuse, N.Y., a corporation of Delaware FiledJuly 5, 1960, Ser. No. 40,585 3 Claims. (Cl. 6265) This inventionrelates to ice making, more particularly to a refrigeration system foruse in conjunction with apparatus for making ice cubes. 7

A variety of equipment has been evolved for producing rectangularlyshaped particles of ice of the so-called ice cube form. In forming theseice cubes in commercial quantities, a grid is generally employedcontaining a plurality of cells confining a volume of the configurationof the ice to be formed, and a movable platen is arranged to close offthe bottom of the grid to retain liquid to be frozen within the cells ofthe grid. Freezing of the liquid in the cells is accomplished bypositioning the evaporator of a compression refrigeration system in heatexchange relationship with said cells whereby the liquid to be frozen,confined within. the cells, may be cooled to freeze After the ice isformed, the platen is lowered to permit harvesting of the ice from thecells of the grid. A preferred icemaking apparatus of this type is shownin co-pending application Serial No. 40,719 filed by William L. McGrathon July 5, 1960, now Patent No. 3,020,- 724.

In effecting refrigeration of the grid cells to form the desired ice, atnumber of problems are encountered due to the desirability of producingice cubes of uniform size and quality. In order to produce a uniformquality of ice cubes, it is necessary that the temperature gradient ofice formation is a function of temperature. temperatures in each of thecells are substantially the same, the ice produced in each of the cellswill not be the same. Where a compression refrigeration system isutilized in providing the desired refrigeration of the grid cells, it isfurther necessary to insure the fact that all of United States Patent'Othe refrigerant flowing through the refrigeration system 7 will be in agaseous state at the time of passage into the suction connection to thecompressor. In effecting release of the formed ice from the grid cells,it is necessary to break the bond between the ice and the cell walls.This can most readily be accomplished by heating of the walls, and as isapparent it would be most desirable to be able to employ therefrigeration system to provide the necessary heat. t

It is with the above problems and desiderata in mind that the presentmeans, including both method and apparatus, have been evolved. The novelmeans embodied in a unique compression refrigeration system serve tocool the liquid to be supplied to the grid, and serve further to permitselective cooling or heating of the cells ofthe grid, with the coolingaction taking place only until all the cells of the grid are tilled withcubes of desired quality at which time beating of the grid may beeffected by the refrigeration system to break any bond between theformed ice and the cell walls. The novel refrigeration system is soarranged as to provide -a uni form cooling gradient across each of thecells of the grid; and further utilizes the refrigeration effectsinvolved in converting the refrigerant into a gas so as to provideefi'icientrefrigeration operation, and insuring the presence of onlygaseous refrigerant in the suction line to the compressor. It isaccordingly 3 primary object of this invention to provide means foreffecting efficient cooling of the cells of a grid and platen type ofice cube forming equipment.

ice

Another object of the invention is to provide means for decreasing thetime required to attain ice cube formation in the cells of a grid andplaten type of ice cube forming equipment.

It is also an object of the invention to provide means for effectivelybreaking any bond between the formed ice cubes and the side walls of thecells of the grid in which said cubes are formed.

An additional object of the invention is to provide means freeing theformed ice from the ice forming grid as soon as possible after thecompletion of the iceforming cycle so that the ice cube formingequipment may be utilized with maximum efficiency.

It is also an object of the invention to provide relatively uniformrefrigeration effects in all the cells of the grid of an ice formingmachine so as to provide uniformity in the ice particles formed.

Another object of the invention is to provide a compressionrefrigeration system for use in ice forming equip ment in which all ofthe refrigerant is converted to a gaseous phase before passage to thecompressor.

A further object of the invention is to utilize all the refrigerationeffects produced in converting the refrigerant to a gas.

These and other objects of the invention which will become hereaftermore apparent are attained by provision of a novel refrigeration systemfor an ice making machine. pression type utilizing a primary andsecondary evaporator in series, with the primary evaporator positionedin heat exchange relationship with the ice forming element, and thesecondary evaporator positioned in heat exchange relationship with thesupply of liquid to be frozen. The liquid line from the condenser of therefrigeration system is arranged in heat exchange relationship with thesuction line to the compressor so as to insure full conversion of therefrigerant to the gaseous phase before passage into the compressor. Bymeans of a by.- pass valve positioned between the compressor and thecondenser, the hot compressed refrigerant from the c0mpressor may be feddirectly to the evaporator to heat the ice forming element to effectbreaking of any bond between the formed ice and the ice forming elementduring the harvesting portion of the ice making cycle.

An important feature of the invention resides in the fact that the useof a secondary evaporator section permits the primary evaporator sectioneffecting ice forming to operate flooded, thereby providing a relativelyuniform refrigerant cooling gradient across the ice forming ele men-t.

Another feature of the invention resides in the fact that the heatexchange between the liquid and suction lines of the refrigerationsystem insures the conversion of the refrigerant to the gaseous phasebefore passage to the compressor.

An additional feature of the invention resides in the fact that all ofthe refrigeration effects produced in converting the refrigerant to avapor phase are utilized.

A further feature of the invention resides in the arrangement of thecooling refrigerant evaporator coils of the novel refrigeration systemin proximity to the lower portions of the grid cells of a grid andplaten type ice making machine whereby the cooler portionof the liquidto be frozen will be placed in heat exchange relationship with theevaporating refrigerant so as to increase'the efficiency with which theice may-be formed. T

It is also a feature of this invention that the novel refrigerationsystem is provided with a bypass line and valve arranged to permitcompressed refrigerant to be passed into heat exchange relationship withthe ice forming element to break the bond between the formed ice and theice forming element.

The novel refrigeration system is of acom The specific structuraldetails of a preferred embodiment of the invention, and their mode offunctioning will be made most manifest and particularly pointed out inclear, concise, and exact terms in conjunction with the accompanyingdrawings, wherein:

FIGURE 1 is a perspective view of a grid and platen type of ice makingmachine with parts broken away to reveal the details thereofillustrative of the type of apparatus in conjunction with which theinstant novel refrigeration system may be employed;

FIGURE 2 is a schematic diagram of the novel refrigeration system hereemployed; and

FIGURE 3 is a circuit diagram illustrating a control means suitable forregulating the operation of the novel refrigeration system and the icemaking apparatus.

Referring now more particularly to the drawings, like numerals in thevarious figures will be taken to designate like parts.

The ice making machine to which the instant refrigeration system isapplied is more fully described in the aforementioned co-pendingapplication. The ice making apparatus here shown in FIGURE 1 is arrangedwithin a rectangular housing 11 formed of sheet metal, or the likerelatively rigid sheet material supported'on a framework 9 of angleirons or the like. A bunker 12 is formed at the bottom of the housing11, and provided with a hinged door 13 permitting access to the interiorof the bunker 12. Leading to the bunker is a chute 14 extending from anopening in horizontal partition 15 arranged above the bunker 12.Vertical partition 16 extends upwardly from horizontal partition 15 andseparates the heat dissipating components of the refrigeration system,to be hereinafter described, from the ice forming equipment, and thewater supply equipment, as seen to the left in FIGURE 1.

The novel refrigeration system which may here be employed with optimumeffectiveness as best seen in FIG- URE 2 comprises a compressor 20constituted by a scaled motor compressor unit such as is conventionallyemployed in compression refrigeration systems. The compressor 20 iscoupled via discharge line 21 to condenser 22 which is connected vialiquid refrigerant line 23 through thermal expansion valve 24 to primaryplaten evaporator 25 in series with secondary water pre-coolingevaporator 26, from which suction line 27 extends back to compressor 20to complete the closed fluid circuit through which refrigerant iscirculated. It will be observed that part of liquid line 23, and suctionline 27 are arranged in heat exchange relationship at 30.

Expansion valve 24 is controlled by means of thermostatic bulb 31arranged in heat exchange relationship with suction line 27 so that theamount of refrigerant flowing from the condenser 22 to the evaporator isregulated in response to the temperature of refrigerant in the suctionline.

A bypass line 32 is extended from discharge line 21 from a point beforecondenser 22 to evaporator 25, permitting the flow of compressedrefrigerant directly from the compressor to the evaporator. Regulationof the flow of refrigerant through the bypass line 32' is effected bymeans of solenoid valve 34 the operation of which will be more fullydescribed hereafter in connection with the novel control means.

The water supply circuit here employed as best seen in FIGURE 1 includesa water Storage sump 35 to which water is fed by water main connection36 which feeds water to sump 35 through any desired control valve means.Sump discharge line 41 leads the water from the sump through pump 42 viaflexible water header supply line 43 to water distribution header 45.The water header distributes the water to' the cells of the ice forminggrid 55. Rod 122 mounted in brackets 124 extends through projectionsfrom the corners of grid 55 and support the grid on framework 9. Aplaten 65 is pivotally mounted on rod 66 carried in bearings 67 onframework 9 to close off the bottom of the grid cells so that liquid tobe frozen may be retained therein. The particular ice making apparatushere employed is provided with a platen arranged beneath the grid cells,with liquid to be frozen supplied to the grid cells via nozzles 48 on awater header 45, and with a water collection pan 70 beneath the grid andplaten as more fully described in the aforementioned co-pendingapplication. It will, however, be appreciated that a variety of othergrid and platen types of refrigeration apparatus may be employed.

The platen 65 is of a plate-like configuration substantially coextensivewith the bottom area of grid 55, and is preferably formed with aserpentine passageway so as to accommodate the tubing employed infabricating evaporator 25. The primary portion of evaporator 25 arrangedwithin the serpentine passageway in platen 65 is connected to thesecondary evaporator portion 26, and to the suction line of therefrigeration system by flexible refrigerant conduits 69 so as to permitmovement of the platen with respect to the relatively fixedrefrigeration system components.

The control circuit illustrated diagrammatically in FIGURE 3 controlsthe operation of the aforedescribed refrigeration system, water supplysystem and grid and platen ice forming components to attain a continuoussupply of uniform ice of desired quality and quantity. An electricalcircuit as shown in FIGURE 3 couples pump motor 100, platen moving gearmotor and refrigeration system compressor motor 106.

Coupled to the compressor motor is an overload relay 107, a startingrelay 108, a running capacitor 109, and a starting capacitor such asconventionally employed in refrigeration system motor compressor units.

The gear motor 85 utilized for effecting movement of the platen withrespect to the plate is coupled to the plate via a crank arm 86 andconnecting rod 87 such as more fully described in co-pending applicationSerial No. 40,718 filed in the name of Carl G. Alt.

In addition to the gear motor cam switch 117, the gear motor energizingcircuit is provided with a gear motor manual switch 130, as shown inFIGURE 3. Gear motor switch is of a single pole double throw type and isprovided to permit manual energization of the gear motor for cleaningpurposes.

Control of the condenser fan motor 101 is provided by means of acondenser fan switch 132. Switch 132 is of a single pole single throwpressure sensitive type. Ranco switch 010-2005 is found suitable for thepurpose. As seen in FIGURE 2 the pressure sensitive element 133 ofswitch 132 is arranged in communication with refrigerant discharge line21 so as to sense the compressor head pressure, whereby the switchingaction will be made a function of this head pressure. Solenoid valve 34is arranged for control of refrigerant flow through the previouslydescribed refrigeration system.

A platen switch 135 of a single pole double throw lever action type isarranged in the circuit of pump motor 100 and solenoid valve 34. Thisplaten switch 135 is arranged so as to close the circuit to the pumpmotor 100 when the platen is in contact with the grid, andsimultaneously close the solenoid valve 34. When the platen moves awayfrom the grid, the solenoid valve is energized to open, and the pumpmotor is deenergized.

A manual control switch 138 is arranged in the circuit to compressormotor 106, pump motor 100, solenoid valve 34, gear motor 85 andcondenser fan motor 101. Manua1 control switch 138 is a three positionswitch which permits manual control of the ice making apparatuscomponents so as to permit: complete shut off of the unit; operation ofonly pump motor 100; or operation of all components. When the apparatusis completely shut off, cam 138 is moved to a position where neithercontact arm engages a contact. To operate only the pump motor, cam138'is moved to a position where the left contact is engaged by the leftcontact arm and the right contact is open. For operation of allcomponents, cam 138' is moved to a position urging each contact armint-o engagement with a contact.

Main control switch 140 serves to automatically control the cycles ofoperation of the ice making apparatus in response to pressure andtemperature conditions. Switch 140 is preferably of the Ranco dualcontrol single pole double throw type. As seen in FIGURE 2, switch 1'40is formed with a pressure sensing cut off element 141 arranged incommunication with suction line 27 of the refrigeration system and atemperature sensitive cut in element 142 arranged to sense thetemperature in the grid cells preferably by being fastened to the grid55. For convenience, the temperature sensitive cut in element 142is'shown in FIGURE 2 to be mounted on the platen of the instant iceforming apparatus.

A bin switch 145 is mounted in the ice storage bin or bunker and isarranged to control the operation of the ice making apparatus inresponse to the quantities of ice produced.

The novel refrigeration means here provided are particularly adapted foruse in conjunction with a grid and platen type of ice making apparatusto effect the uniform freezing of liquid to be frozen in the cells ofthe ice forming grid so as to produce uniform quality ice cubes in eachof the grid cells at a relatively rapid rate. The novel refrigerationsystem as best seen in FIGURES 1 and 2 is of a compression refrigerationtype in which the compressor 20, condenser 22, and two part evaporator25, 26 are arranged in a fluid circuit through which refrigerant may becirculated.

The compressor 20 compresses refrigerant in its gaseous phase, anddischarges the high pressure high temperature refrigerant vapor into theair cooled condenser 22 which is in heat exchange relationship with theambient air. Depending on the temperature of the ambient air, and thepressure in discharge line- 21, condenser fan motor 101 will be set intooperation. Thus if additional cooling is required to lower the headpressure in line 21 the fan motor will be operated to increase the rateof air flow over the condenser coils, or if head pressures are too low,the fan motor will be quiescent so as to minimize the rate of heatexchange between the ambiance and the refrigerant in the condenser,whereby refrigerant head pressures will build up in the refrigerationsystem.

' From the condenser, during the normal refrigeration cycle, thecondensed refrigerant vapor now in a liquid phase, flows through liquidline 23 to thermal expansion valve 24.

Expansion valve 24 meters refrigerant into primary evaporator portion 25which is in heat exchange relationship with the cells of the ice forminggrid. In the illustrated embodiment of the invention; this isaccomplished by arranging evaporator 25- within the platen of the iceforming apparatus. Inthe primary evaporator 25, the refrigerant absorbsheat from the liquid to be frozen in the grid cells. The heat absorbedserves to vaporize the refrigerant in evaporator 25 which then flowsinto secondary evaporator 26 arranged to direct the evaporatingrefrigerant therein int-o heat exchange relationship with the supply ofliquid to be frozen in the supply sump. The secondary evaporator may bedisposed in the liquid in the sump or may be arranged adjacent the sump.This two part evaporator arrangement serves to substantially insureflooded operation of primary evaporator 25, whereby uniform refrigeranteffects in each of the grid cells will be obtained; thus producinguniform ice cubes.

In addition, during the freezing cycle a body of liquid adjacent thesecondary evaporator 26 is solidified. During the defrost cycle, thecondensing refrigerant flows through the secondary evaporator 26 andfrees the ice formed adjacent the secondary evaporator. The ice rises tothe top of the liquid in the sump 35. At the initiation of the nextcycle, (this ice is used to additionally cool the incoming warm liquidto be frozen.

6 From secondary evaporator 26, the refrigerant vapor flows through thesuction line 27 where any moisture in the vapor will be furthervaporized as a result of the action of the high temperature refrigerantin discharge line 21. Vaporized refrigerant flows back to the compressorthrough suction line 27 for recycling through the refrigeration system.

After the desired ice is formed in the grid cells, the refrigerationsystem may be employed to break the bond between the for-med ice and thegrid cell walls by closing valve 34 which causes compressed refrigerantfrom compressor 20 to be diverted through bypass line 32 to evaporator25. The diverted condensing refrigerant heats the grid to free theformed ice.

It is thus seen that an improved refrigeration system has been providedfor use in conjunction with a grid and platen type of ice makingapparatus for both freezing and defrosting of the formed ice. The use ofa flooded evaporator in heat exchange relationship with the ice forminggrid cells permits the relaitvely uniform cooling of all of the gridcells to form ice of uniform quality. Additionally, the heat exchangerin the suction line of the compressor insures vaporization of therefrigerant prior to entering to the compressor.

The above disclosure 'has been given by way of illustration andelucidation, and 'not by way of limitation, and it is desired to protectall embodiments of the hereindisclosed inventive concept within thescope of the appended claims.

I claim: 1. In an ice maker, the combination of an ice forming element,a supply sump for liquid to be frozen, means for supplying the liquidfrom the supply sump to the ice form-' ing element, and means forrefrigerating the ice forming element, said refrigerating meanscomprising primary heat absorbing refrigerant evaporating means in heatexchange relationship with the ice forming element; secondary heatabsorbing refrigerant evaporating means in contact with the liquid to befrozen in the supply sump to form ice on a portion thereof, saidsecondary means being in fluid communication with said primary meansreceiving liquid refrigerant therefrom to insure the presence of liquidrefrigerant throughout said primary means whereby uniform refrigerationeffects will be produced throughout the ice forming element, means fordiscontinuing refrigeration of the ice forming element and the supply ofliquid refrigerant to the secondary means, and means for supplyinggaseous refrigerant to the primary means and to the secondary means tofree ice therefrom, ice freed from the secondary means remaining in thesump to cool incoming warm liquid to be frozen.

2. In a method of refrigerating an ice forming element having a supplysump for liquid to be frozen, the steps which consist in evaporatingliquid refrigerant in heat exchange relation with the ice formingelement, passing liquid refrigerant remaining after its passage throughthe ice forming element through a secondary evaporator in the sump incontact with liquid to be frozen in the sump thereby forming ice on thesecondary evaporator and providing a uniformrefrigerating effectthroughout the ice forming element, discontinuing passage of liquidrefrigerant to the ice forming element and the secondary evaporator,passing gaseous refrigerant through the ice forming element and thesecondary evaporator to free ice therefrom, and employing the ice freedfrom the secondary means remaining in the sump to cool incoming warmliquid to be frozen.

3. In an ice maker, the combination of a grid having a plurality ofcells therein in which liquid to be frozen may a. condenser receivingcompressed refrigerant from the compressor, a primary evaporator in saidplaten coupled to said condenser via an expansion valve metering thecondensed refrigerant to said primary evaporator, a secondary evaporatorin said sump coupled to said primary evaporator to receive liquidrefrigerant therefrom and to said compressor to supply gaseousrefrigerant thereto, said secondary evaporator being placed in contactwith liquid in said sump to form ice on a portion thereof, said primaryevaporator operating flooded during the freezing operation to provideuniform refrigerating effects over the platen so as to uniformly freezethe liquid confined in the cells of the grid, appropriate refrigerantconduits connecting said compressor, condenser, expansion valve, primaryevaporator, and secondary evaporator in such order to form a closedcircuit through which refrigerant may flow, means for discontinuing thesupply of condensed refrigerant to said primary and secondaryevaporators, and means for supplying gaseous refrigerant to said primaryevaporator and to said secondary evaporator to free ice therefrom, icefreed from the secondary evaporator remaining in the sump to coolincoming warm liquid to be frozen.

7 References Cited in the file of this patent UNITED STATES PATENTS666,703 Seilacker Ian. 29, 1901 894,285 Rasshach July 28, 1908 1,322,660Voorhees Nov. 25, 1919 2,259,920 Baer Oct. 21, 194 1 2,613,506 Cook Oct.14, 1952 2,701,453 Henderson Feb. 8, 1955 2,737,024 Swenson Mar. 6, 19562,739,457 Chapman Mar. 27, 1956 2,775,100 Howe Dec. 25, 1956 2,949,752Bayston Aug. 23, 1960 FOREIGN PATENTS 238,325 Switzerland Oct. 16, 1945

